Dont forget mistakes: capital punishment, unlike other sentences, is hard to undo once it is complete.
England discovered someone was innocent 53 years after they were killed by the state.
http://forejustice.org/wc/george_kelly.htm
And: Forensic and Police Experts purposely fudging reports to convict persons.
http://www.corpus-delicti.com/forensic_fraud.html
Makes you wonder how many wrongfully accused people have been killed by state governments or sentenced to be killed.
http://www.theatlantic.com/issues/99...11wrongman.htm